Analyzing the effect of the SIX1/EYA2 protein complex on leukemogenesis
Mentor Name: Daniel Wechsler
Patients with acute myeloid leukemia (AML) harboring an AF10 fusion oncogene have a poor prognosis--a 5-year survival rate of less than 10%. The CALM-AF10 fusion occurs in AML and aberrantly activates proleukemic HOXA genes. Given the critical nature of HOXA genes, we used RNAseq and microarrays to identify novel targets of CALM-AF10 and found that the homeobox protein SIX1 (Sine Oculis Homeobox 1) is activated by CALM-AF10. We further determined that overexpression of the SIX1 protein in hematopoietic stem cells (HSCs) is sufficient for immortalization. The proposed work will evaluate the role of the SIX1 protein with its cofactor EYA2 (Eyes Absent 2) in driving this immortalization. Using wild type and mutant SIX1 and EYA2 proteins, we will determine if the interaction of SIX1 and EYA2 is necessary for immortalization. Further, we will use inhibitors of the SIX1/EYA2 interaction (8430) and an allosteric inhibitor of EYA2 (9987) in combination with the wild-type and mutant proteins in the HSCs to help determine the importance of SIX1, EYA2, and their interaction in the HSC immortalization. Finally, we will also use these inhibitors in combination with the CRM1 inhibitor Selinexor in CALM-AF10 leukemia cells to assess synergy between the inhibitors based on their differing sites of action in the activation of SIX1 by CALM-AF10.
